French Patent 2,357,490 discloses a biological septic tank activator, in the form of a non-corrosive, non-toxic finely divided product of large specific area, which forms a support for the optional anaerobic microbial flora. The activator enables the bacterial saturation density in the septic tank to be increased for an equivalent quantity of nutrients and comprises: firstly a colloidal phase in suspension and, secondly, a flocculent phase. The patent discloses that the specific area of the biological activator is less than 1 m.sup.2 /g. Also, the cation exchange capacity of a known biological activator of this kind may be put at about 9 meq/100 g.
Kaolinite particles are used per se as biological activators. However, use of kaolinic clays as the principal basic component of prior biological activators limits the values of the useful parameters for the biological activation function for a septic tank because of the actual physico-chemical characteristics of such clays. It is particularly the specific area and cationic exchange capacity which are limited depending upon the actual composition of the kaolinic clays. The specific area and cationic exchange capacity are important parameters in a biological activator. Inasmuch as these two parameters determine the ion exchanges, the absorption of organic substrates, and the fixation of bacteria and enzymes, the values for these parameters should be as high as possible in order to provide optimum biological activation of a septic tank.
A mixture of natural zeolites has been produced and sold under the trademark ZEOPORT B180. This product is known to have high porosity, high exchange capacity and the ability to absorb certain gaseous molecules. However, because this product has a high pH and brings oxygen which is detrimental for anaerobic bacteria, it has no, and in fact can have no, activation effect for use in a septic tank.